xpathparser.java

java1.6众多例子参考

        }
        else
        {
          insertOp(addPos, 2, OpCodes.OP_GT);
        }

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = RelationalExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
    }

    return addPos;
  }

  /**
   * This has to handle construction of the operations so that they are evaluated
   * in pre-fix order.  So, for 9+7-6, instead of |+|9|-|7|6|, this needs to be
   * evaluated as |-|+|9|7|6|.
   *
   * AdditiveExpr  ::=  MultiplicativeExpr
   * | AdditiveExpr '+' MultiplicativeExpr
   * | AdditiveExpr '-' MultiplicativeExpr
   *
   *
   * @param addPos Position where expression is to be added, or -1 for append.
   *
   * @return the position at the end of the equality expression.
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected int AdditiveExpr(int addPos) throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    if (-1 == addPos)
      addPos = opPos;

    MultiplicativeExpr(-1);

    if (null != m_token)
    {
      if (tokenIs('+'))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_PLUS);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = AdditiveExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
      else if (tokenIs('-'))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_MINUS);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = AdditiveExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH, 
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
    }

    return addPos;
  }

  /**
   * This has to handle construction of the operations so that they are evaluated
   * in pre-fix order.  So, for 9+7-6, instead of |+|9|-|7|6|, this needs to be
   * evaluated as |-|+|9|7|6|.
   *
   * MultiplicativeExpr  ::=  UnaryExpr
   * | MultiplicativeExpr MultiplyOperator UnaryExpr
   * | MultiplicativeExpr 'div' UnaryExpr
   * | MultiplicativeExpr 'mod' UnaryExpr
   * | MultiplicativeExpr 'quo' UnaryExpr
   *
   * @param addPos Position where expression is to be added, or -1 for append.
   *
   * @return the position at the end of the equality expression.
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected int MultiplicativeExpr(int addPos) throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    if (-1 == addPos)
      addPos = opPos;

    UnaryExpr();

    if (null != m_token)
    {
      if (tokenIs('*'))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_MULT);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = MultiplicativeExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
      else if (tokenIs("div"))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_DIV);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = MultiplicativeExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
      else if (tokenIs("mod"))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_MOD);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = MultiplicativeExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
      else if (tokenIs("quo"))
      {
        nextToken();
        insertOp(addPos, 2, OpCodes.OP_QUO);

        int opPlusLeftHandLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - addPos;

        addPos = MultiplicativeExpr(addPos);
        m_ops.setOp(addPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(addPos + opPlusLeftHandLen + 1) + opPlusLeftHandLen);
        addPos += 2;
      }
    }

    return addPos;
  }

  /**
   *
   * UnaryExpr  ::=  UnionExpr
   * | '-' UnaryExpr
   *
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void UnaryExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);
    boolean isNeg = false;

    if (m_tokenChar == '-')
    {
      nextToken();
      appendOp(2, OpCodes.OP_NEG);

      isNeg = true;
    }

    UnionExpr();

    if (isNeg)
      m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
        m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);
  }

  /**
   *
   * StringExpr  ::=  Expr
   *
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void StringExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    appendOp(2, OpCodes.OP_STRING);
    Expr();

    m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
      m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);
  }

  /**
   *
   *
   * StringExpr  ::=  Expr
   *
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void BooleanExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    appendOp(2, OpCodes.OP_BOOL);
    Expr();

    int opLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos;

    if (opLen == 2)
    {
      error(XPATHErrorResources.ER_BOOLEAN_ARG_NO_LONGER_OPTIONAL, null);  //"boolean(...) argument is no longer optional with 19990709 XPath draft.");
    }

    m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH, opLen);
  }

  /**
   *
   *
   * NumberExpr  ::=  Expr
   *
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void NumberExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    appendOp(2, OpCodes.OP_NUMBER);
    Expr();

    m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
      m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);
  }

  /**
   * The context of the right hand side expressions is the context of the
   * left hand side expression. The results of the right hand side expressions
   * are node sets. The result of the left hand side UnionExpr is the union
   * of the results of the right hand side expressions.
   *
   *
   * UnionExpr    ::=    PathExpr
   * | UnionExpr '|' PathExpr
   *
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void UnionExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);
    boolean continueOrLoop = true;
    boolean foundUnion = false;

    do
    {
      PathExpr();

      if (tokenIs('|'))
      {
        if (false == foundUnion)
        {
          foundUnion = true;

          insertOp(opPos, 2, OpCodes.OP_UNION);
        }

        nextToken();
      }
      else
      {
        break;
      }

      // this.m_testForDocOrder = true;
    }
    while (continueOrLoop);

    m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);
  }

  /**
   * PathExpr  ::=  LocationPath
   * | FilterExpr
   * | FilterExpr '/' RelativeLocationPath
   * | FilterExpr '//' RelativeLocationPath
   *
   * @throws XSLProcessorException thrown if the active ProblemListener and XPathContext decide
   * the error condition is severe enough to halt processing.
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void PathExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    int filterExprMatch = FilterExpr();

    if (filterExprMatch != FILTER_MATCH_FAILED)
    {
      // If FilterExpr had Predicates, a OP_LOCATIONPATH opcode would already
      // have been inserted.
      boolean locationPathStarted = (filterExprMatch==FILTER_MATCH_PREDICATES);

      if (tokenIs('/'))
      {
        nextToken();

        if (!locationPathStarted)
        {
          // int locationPathOpPos = opPos;
          insertOp(opPos, 2, OpCodes.OP_LOCATIONPATH);

          locationPathStarted = true;
        }

        if (!RelativeLocationPath())
        {
          // "Relative location path expected following '/' or '//'"
          error(XPATHErrorResources.ER_EXPECTED_REL_LOC_PATH, null);
        }

      }

      // Terminate for safety.
      if (locationPathStarted)
      {
        m_ops.setOp(m_ops.getOp(OpMap.MAPINDEX_LENGTH), OpCodes.ENDOP);
        m_ops.setOp(OpMap.MAPINDEX_LENGTH, m_ops.getOp(OpMap.MAPINDEX_LENGTH) + 1);
        m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
          m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);
      }
    }
    else
    {
      LocationPath();
    }
  }

  /**
   *
   *
   * FilterExpr  ::=  PrimaryExpr
   * | FilterExpr Predicate
   *
   * @throws XSLProcessorException thrown if the active ProblemListener and XPathContext decide
   * the error condition is severe enough to halt processing.
   *
   * @return  FILTER_MATCH_PREDICATES, if this method successfully matched a
   *          FilterExpr with one or more Predicates;
   *          FILTER_MATCH_PRIMARY, if this method successfully matched a
   *          FilterExpr that was just a PrimaryExpr; or
   *          FILTER_MATCH_FAILED, if this method did not match a FilterExpr
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected int FilterExpr() throws javax.xml.transform.TransformerException
  {

    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    int filterMatch;

    if (PrimaryExpr())
    {
      if (tokenIs('['))
      {

        // int locationPathOpPos = opPos;
        insertOp(opPos, 2, OpCodes.OP_LOCATIONPATH);

        while (tokenIs('['))
        {
          Predicate();
        }

        filterMatch = FILTER_MATCH_PREDICATES;
      }
      else
      {
        filterMatch = FILTER_MATCH_PRIMARY;
      }
    }
    else
    {
      filterMatch = FILTER_MATCH_FAILED;
    }

    return filterMatch;

    /*
     * if(tokenIs('['))
     * {
     *   Predicate();
     *   m_ops.m_opMap[opPos + OpMap.MAPINDEX_LENGTH] = m_ops.m_opMap[OpMap.MAPINDEX_LENGTH] - opPos;
     * }
     */
  }

  /**
   *
   * PrimaryExpr  ::=  VariableReference
   * | '(' Expr ')'
   * | Literal
   * | Number
   * | FunctionCall
   *
   * @return true if this method successfully matched a PrimaryExpr
   *
   * @throws javax.xml.transform.TransformerException
   *
   */
  protected boolean PrimaryExpr() throws javax.xml.transform.TransformerException
  {

    boolean matchFound;
    int opPos = m_ops.getOp(OpMap.MAPINDEX_LENGTH);

    if ((m_tokenChar == '\'') || (m_tokenChar == '"'))
    {
      appendOp(2, OpCodes.OP_LITERAL);
      Literal();

      m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH, 
        m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);

      matchFound = true;
    }
    else if (m_tokenChar == '$')
    {
      nextToken();  // consume '$'
      appendOp(2, OpCodes.OP_VARIABLE);
      QName();
      
      m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
        m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);

      matchFound = true;
    }
    else if (m_tokenChar == '(')
    {
      nextToken();
      appendOp(2, OpCodes.OP_GROUP);
      Expr();
      consumeExpected(')');

      m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
        m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);

      matchFound = true;
    }
    else if ((null != m_token) && ((('.' == m_tokenChar) && (m_token.length() > 1) && Character.isDigit(
            m_token.charAt(1))) || Character.isDigit(m_tokenChar)))
    {
      appendOp(2, OpCodes.OP_NUMBERLIT);
      Number();

      m_ops.setOp(opPos + OpMap.MAPINDEX_LENGTH,
        m_ops.getOp(OpMap.MAPINDEX_LENGTH) - opPos);

      matchFound = true;